complete issue - IMA Fungus
complete issue - IMA Fungus
complete issue - IMA Fungus
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the wild yeasts were beneficial to growth<br />
under 12 sets of conditions tested. In yeasts,<br />
it has consequently now been established<br />
that prions are a naturally present<br />
supplementary source of inheritable material<br />
of adaptive value. The extent of prions in<br />
filamentous fungi as a whole has yet to be<br />
assessed, but they clearly have the potential<br />
to contribute to adaptability and fitness.<br />
volume 3 · no. 1<br />
Halfmann R, Jarosz DF, Jones SK, Change A,<br />
Lancaster AK, Lindquist S (2012) Prions<br />
are a common mehcnisms for phenotypic<br />
inheritance in wild yeasts. Nature 282:<br />
363–368.<br />
True HL, Lindquist SL (2000) A yeast prion<br />
provides a mechanism for genetic variation<br />
and phenotypic diversity. Nature 407:<br />
477–478.<br />
Different fungal and algal genotypes demonstrated<br />
within one lichen specimen<br />
Observations on the development of lichens<br />
in the field reveal that multiple propagules<br />
of a species developing on a surface often<br />
116<br />
P4T7e<br />
104<br />
P3T4c<br />
108<br />
P4T7<br />
102<br />
P3T4<br />
113<br />
P1T8<br />
103<br />
P5T3<br />
106<br />
P5T3c<br />
123<br />
P4T7d<br />
A single specimen of Parmotrema tinctorum showing the different fungal<br />
and algal genotypes determined with PCR of SSR markers. Codes prefixed<br />
by P are of the fungal partner, and those by T are of the algal partner; five<br />
fungal genotypes and one algal genotype were detected within this particular<br />
98<br />
specimen. P3T6 Adapted from Mansournia et al. (2012).<br />
Yeast colonies, light and tramsmission electron<br />
micrograph photos of Saccharomyces cerevisiae.<br />
coalesce to form a single structure. This is<br />
frequently observed where the propagules<br />
are asexual soredia or isidia, which may<br />
or may not have<br />
come from the same<br />
parent, and is welldocumented.<br />
However,<br />
whether all had to be<br />
of a single genotype<br />
for this to occur was<br />
uncertain. The first<br />
study to suggest that a<br />
single lichen specimen<br />
might not just have a<br />
single fungal partner<br />
experimentally was<br />
the study of Larson<br />
& Carey (1986) who<br />
found that single<br />
115<br />
P6<br />
Tabcde<br />
120<br />
P6<br />
Tabcde<br />
124<br />
P6<br />
Tabcde<br />
specimens of two<br />
Umbilicaria species<br />
showed variations<br />
in physiological<br />
parameters and<br />
isoenzyme profiles.<br />
With the advent<br />
of DNA PCR<br />
technology, and<br />
especially the use of<br />
microsatellite (SSR)<br />
markers, it has become<br />
possible to explore the<br />
<strong>issue</strong> of the degree of<br />
individuality of single<br />
lichen specimens<br />
with respect to both<br />
the fungal and the<br />
algal populations that<br />
comprise them.<br />
Parmotrema tinctorum is a rather<br />
common tropical lichen that reproduces<br />
mainly by asexual isidia. Mansornia et<br />
al. (2012) studied populations growing<br />
on Pinus thunbergii in Japan, and used<br />
microsatellite markers to characterize the<br />
partners at different levels: within single<br />
specimens, on single trees, and within 10 x<br />
10 cm quadrats. Of particular interest were<br />
the results from single specimens in which<br />
they studied numerous small pieces of t<strong>issue</strong>.<br />
They found that a single specimen could be<br />
formed from a single fungal partner with<br />
or without changes in the algal partner,<br />
or fusion of several independent partners.<br />
In total 12 fungal genotypes and 37 algal<br />
genotypes were recognized. An example in<br />
which there were five fungal genotypes and<br />
a single algal genotype is illustrated here.<br />
Further, specimens from individual trees<br />
or which were close together tended to<br />
have similar genotypes, suggesting limited<br />
dispersal in the site.<br />
This study provides evidence to support<br />
what has long been suspected, that one<br />
cannot presume that what looks like a single<br />
individual lichen specimen represents a<br />
single fungal genotype.<br />
Larson DW, Carey CK (1986) Phenotypic variation<br />
within “individual” lichen thalli. American<br />
Journal of Botany 73: 214–223.<br />
Mansournia MR, Wu B, Matsushita N, Hogetsu T<br />
(2012) Genotypic analysis of the foliose lichen<br />
Parmotrema tinctorum using microsatellite<br />
markers: association of mycobiont and<br />
photobiont, and their reproductive modes.<br />
Lichenologist 44: 419–440.<br />
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